1. Field of the Invention
The present invention relates to an electrical connector, and more particularly to a land grid array (LGA) connector for electrically connecting an electronic package such as an LGA chip and a circuit substrate such as a printed circuit board (PCB).
2. Description of the Prior Art
Land grid array (LGA) electrical connectors are widely used in the connector industry for electrically connecting LGA chips to printed circuit boards (PCBs) in personal computers (PCs). Conventionally, one kind of the LGA connector mainly comprises an insulative housing, a multiplicity of contacts received therein, a metallic stiffener partly covering and reinforcing the housing, and a metal clip and a cam lever pivotably mounting on two opposite sides of the stiffener. The housing defines a multiplicity of terminal passageways in a rectangular array, for interferentially receiving corresponding terminals. Due to the very high density of the terminal array that an LGA chip may have, the LGA chip needs to be precisely seated on the LGA connector. This is to ensure reliable signal transmission between the terminals and the LGA chip.
Referring to FIG. 4, such a conventional LGA connector 8 typically comprises an insulative housing 80, a plurality of electrical contacts 81 received in corresponding passageways (not labeled) of the housing 80, a metal stiffener 82 partly covering and reinforcing the housing 80, a cam lever 84 pivotably received in a chamber 820 with a U-shaped cross-section of the stiffener 82, and a metal clip 83 pivotably mounted to an opposite rear end 821 with an L-shaped cross-section of the stiffener 82 for engaging with the cam lever 84. The housing 80 defines four sidewalls (not labeled) and a central cavity disposed between the sidewalls. The central cavity is used for receiving a land grid array (LGA) chip (not shown) therein. Each contact 81 has a contact portion protruding outwardly from an upper surface of the housing 80, for electrically connecting with a corresponding metal contact pad of the LGA chip that is received in the LGA connector 8, and a solder portion mounted on a printed circuit board (PCB) (not shown) via a surface mounted solder ball (not shown). The clip 83 comprises two opposite sides 830. A pair of pressing portions 831 is provided in respective middle portions of the sides 830, for pressing the LGA chip engaging with the terminals 81.
When the LGA connector 8 is electrically connected the LGA chip, firstly, engaging the LGA chip with the LGA connector 8, the clip 83 is rotated upward. The LGA chip is placed in the central cavity of the housing 80. The clip 83 is rotated from a vertical portion to a horizontal portion to make the two opposite sides 830 of the clip 83 attach on corresponding sides of the LGA chip. The cam lever 84 is rotated to drive the clip 83 to gradually approach the housing 80 until the pressing portions 831 of the clip 83 press the LGA chip downwardly to make the contact pads of the LGA chip contact with the contact portions of the terminals 81 and make the LGA chip received in the central cavity therein. As a result, mechanical and electrical engagement between the LGA chip and the LGA connector 8 is attained.
However, the stiffener 82 is integrately formed as a single piece metal by stamping and passed through a plating process to increase its wearable performance. Because the front end 820 of the stiffener 82 has a U-shaped cross-section chamber (not labeled). In a plating process, the plating solute is not easy to fill in the whole chamber of the stiffener 82 to result in the chamber of the stiffener 82 plating asymmetrically. When this happens, reliable wearable performance of the stiffener 82 will be destroyed. The LGA connector 8 may not reliably electrically connect with the LGA chip.
Thus, there is a need to provide a new LGA connector that overcomes the above-mentioned problems.